2021 Chevy Duramax L5P - 21,900 miles/503 hours on oil - 43,400 total miles/997 total hours - HPL 5w-40

[dnewton3]

Regarding the soot loading, it's generally accepted in heavy rigs that 5% is a condemnation point. I believe that Cummins, Mack and others use this limit. Not sure if Volvo also uses that value.

- PC analysis can tell us the size of particulate and the loading percentages, but they cannot tell us the composition.
- UOAs can tell us the composition of the elements found, but not size (though we know they are limited to seeing around 5um or smaller because that's the practical limit of how ICP tech works). Therefore we can only project a theory of what lays in the oil above 5um when it comes to metals, etc.

I think there is value in looking into BP filters if wwillson is going to extend much further. They will bring the soot down. Greatly extended OCIs are the best application for BP filtration.

 

[SEBZX79]

I had a 2021 that we put 195k miles on in less than 2 years.
Engine is good ( clean the air pressure sensor every oil change)
Issues with injector connectors especially number 7.
Def tank heater issues
Trans oil change at 50 to 60k
Rear diff at 50 to 60k
Front diff and transfer case at 100k
You should be good to go.

 

[wwillson]

clean the air pressure sensor every oil change

Do you mean the TMAP senosor? It definitely needs to be cleaned at every oil change.

GM L5P TMAP (Temperature & Manifold Absolute Pressure) sensor clogged with soot at 17,500 miles - S&B MAP spacer

I have read many threads on diesel forums about the somewhat problematic TMAP sensor on the L5P Duramax. The sensor sits in the intake and can collect enough soot from the EGR that it can malfunction and cause rough idle and drivability problem or throw a code, which could leave you sitting...

bobistheoilguy.com

Issues with injector connectors especially number 7

I'm curious if you ran a fuel injector cleaner like Power Service? Do you have any indication of why #7 is problematic? I've read this many places.

transfer case at 100k

I change the transfer case fluid every time I change the oil (~20k-25k). It's so easy to do that I figure why not.

 

[SEBZX79]

Do you mean the TMAP senosor? It definitely needs to be cleaned at every oil change.

GM L5P TMAP (Temperature & Manifold Absolute Pressure) sensor clogged with soot at 17,500 miles - S&B MAP spacer

I have read many threads on diesel forums about the somewhat problematic TMAP sensor on the L5P Duramax. The sensor sits in the intake and can collect enough soot from the EGR that it can malfunction and cause rough idle and drivability problem or throw a code, which could leave you sitting...

bobistheoilguy.com

I'm curious if you ran a fuel injector cleaner like Power Service? Do you have any indication of why #7 is problematic? I've read this many places.


I change the transfer case fluid every time I change the oil (~20k-25k). It's so easy to do that I figure why not.

It's the pigtail connector that's problematic. Dealer replaced the injector as a precaution. (Been a issue since the beginning of L5p I don't think gm correct it ever.
I think that's over kill on the TC but if it makes you feel good go for it.

 

[wwillson]

I think that's over kill on the TC but if it makes you feel good go for it.

It may be, but if you shoot it with a IR thermometer, it runs hot. The oil that drains out at 25k miles is darkening. It makes me feel great!

 

[SEBZX79]

We ran what ever cheapest 15w40 I could find in the summer and 5w40 in the winter.
Driver would idle the truck for 10 plus hours a day and then run it hard for 11 plus. Oil was changed every 460 to 500 hours. Over 6400 hours on engine at 195k

 

[CleverUserName]

It will be a 50 weight oil soon. The iron wear rate is increasing don’t see the point in keeping it in any longer as boron is already depleted. If it were my engine it’s not worth causing accelerated wear to squeeze out a few more thousand miles of oil life for bragging rights.

 

[wwillson]

The iron wear rate is increasing don’t see the point in keeping it in any longer as boron is already depleted

The HPL CK-4 formula doesn't have boron. What you see on the UOA is noise. The Fe rate/1k miles is not increasing. I see zero reason to change this oil.

 

[wwillson]

It will be a 50 weight oil soon.

The range for SAE 50 is 16.30-21.89. The oil is 15.2 now and it has a quite a way to get to a 50. If it does get to SAE 50 before it gets changed, it certainly won't hurt anything. Remember VIIs in this oil don't shear, so you see all of the thickening. Most oils will shear, so the oxidative thickening is offset by shearing.

 

[wwillson]

Al is low.

I attribute the low AL to being very mindful to keep the EGTs as low as possible while towing tall and heavy. It's a challenge sometimes to keep the EGTs below 1000°F on the flat with a headwind and below 1200°F towing uphill for short durations. With the power these modern diesels put out, it would be easy to run 1300°-1400°F for long stretches and that's not a good thing.

 

[fantastic]

I attribute the low AL to being very mindful to keep the EGTs as low as possible while towing tall and heavy. It's a challenge sometimes to keep the EGTs below 1000°F on the flat with a headwind and below 1200°F towing uphill for short durations. With the power these modern diesels put out, it would be easy to run 1300°-1400°F for long stretches and that's not a good thing.

Very good! Keeping things cool is the primary goal. No need to add extra heat just to arrive a few min. early right.

What are your typical camper hauling speeds (MPH)?

 

[wwillson]

What are your typical camper hauling speeds (MPH)?

I tow at 60 or 65, depends on the road and the conditions.

 

[wpod]

The oil is still in the 40 range the metals aren't bad , I don't know about the soot numbers to comment . I would say the oil is still serviceable. HPL certainly blends some high quality oil.